Electrical devices such as occupancy sensors and motion detectors have become commonplace in both residential and commercial construction applications. Proper installation of these devices requires that they be placed accurately to perform their desired function. Moreover, since the proper functioning of these devices is sensitive to their placement it is desirable for an installer to be able to install, replace, repair and inspect these devices without extensive disassembly or displacement of these units from the locations in which they were originally installed.
Today, automation systems that include sensors are being installed in more and more buildings, including both new construction and structures that are being rebuilt. The incentives for putting automation systems into a building are numerous. High on the list are occupancy sensors to help reduce costs by turning off lights when a person leaves a room, more efficient use of energy, simplified control of building systems, ease of maintenance and of effecting changes to the systems. Facility managers would prefer to install systems that can interoperate amongst each other. Interoperability is defined by different products, devices and systems for different tasks and developed by different manufacturers, being able to be linked together to form flexible, functional control networks.
An example of a typical automation system includes security systems that include occupancy sensors and/or lighting controls, HVAC systems, etc., all possibly provided by different manufacturers. It would be desirable therefore if these separate disparate systems could be quickly and easily mounted to a standard outlet box.
Prior art systems generally comprise closed proprietary equipment supplied by a single manufacturer. In these systems, the installation, servicing and future modifications of the component devices in the systems are restricted to a single manufacturer's product offering and technical capability. In addition, it is very difficult or impossible to integrate new technology developed by other manufacturers. In the instances where technology from other manufactures can be integrated, it is usually too costly to consider.
It is desirable, therefore, to create a system wherein individual sensors, processors and other components can be easily mounted to an outlet box. A few of the benefits of using an open system include an increased number of design options for the facility manager, lower design and installation costs, since the need for customized hardware is greatly reduced, and simplified and quicker system startup.
An integral part of any automated control system are the sensors and transducers used to gather data on one or more physical parameters such as occupancy or motion for example. It would be desirable, therefore, if a plurality of sensor functions could be quickly and easily fitted into a standard single wall box opening and be able to be powered and communicate with one or more control units, i.e., processing nodes, on the control network.
The number and types of sensors in this device could be many including multiple, dual or singular occupancy and security sensing via means including passive infrared, ultrasonic, RF, audio or sound or active infrared. In addition, other multiple or singular transducers may be employed such as temperature sensor, relative humidity sensor, ambient light sensor, CO sensor, smoke sensor, security sensor, air flow sensors, switches, etc.
The utility of such a multifunction sensor can best be described by an example. In order to minimize the number of unique devices that are installed in a room, it is desirable to have a sensor device reliably perform as many functions as possible as this reduces the wiring costs as well as the number of devices required to be installed on the walls of the room. Additionally, from an aesthetic point of view, architects are under increasing demand by their clients to reduce the number of unique sensor nodes in any given room.
Further, it is also desirable to have these transducers or sensors communicate with a microprocessor or microcontroller that can be used to enhance the application of the transducer and be powered by a stand alone unit which includes both the sensor and the power pack which can be a printed circuit board including components in a single enclosure.
At the present time low voltage sensors such as occupancy sensors can be wired to a relay or dimmer panel, or to a localized power pack that houses a single load relay and generates the low voltage power for the sensor. Another option of wiring low voltage sensors is with a stand-alone unit that includes both the occupancy sensor and the power pack in a single enclosure. This approach can be problematic in that it usually requires a manufacturer to produce an additional product line to fulfill the stand-alone requirements that is costly and inefficient.